Ports handler settings reading to Rust

Cargo.toml

@@ -73,6 +73,7 @@ arrayvec = "0.7"
 base64 = "0.13"
 clap = { version = "4.6", features = ["cargo", "string", "wrap_help", "derive"] }
 config = { version = "=0.15.25", default-features = false, features = ["ini"] }
+cxx = "=1.0.198"
 httparse = "1.7"
 ipnet = "2"
 jsonwebtoken = "9"
@@ -109,6 +110,7 @@ test-log = "0.2"
 pkg-config = "0.3"
 time = { version = "0.3.36", features = ["formatting", "local-offset", "macros"] }
 cbindgen = "0.27"
+cxx-build = "=1.0.198"
 
 [[bench]]
 name = "memorypool"

build.rs

@@ -454,6 +454,10 @@ fn main() -> Result<(), Box<dyn Error>> {
         },
     );
 
+    cxx_build::bridge("src/handler/settings.rs")
+        .flag_if_supported("-std=c++17")
+        .compile("pushpin-cxxbridge");
+
     let (qmake_path, qt_version) = get_qmake()?;
 
     let qt_install_libs = {
@@ -516,6 +520,12 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     include_paths.push(cpp_build_dir.as_ref());
 
+    // Headers generated by cxx_build
+    let cxx_include_dir = out_dir.join("cxxbridge").join("include");
+    let cxx_crate_dir = out_dir.join("cxxbridge").join("crate");
+    include_paths.push(cxx_include_dir.as_ref());
+    include_paths.push(cxx_crate_dir.as_ref());
+
     if boost_include_dir != Path::new("/usr/include") {
         include_paths.push(boost_include_dir.as_ref());
     }

src/bin/pushpin-handler.rs

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2023-2025 Fastly, Inc.
+ * Copyright (C) 2023-2026 Fastly, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,20 +15,69 @@
  */
 
 use clap::Parser;
-use pushpin::handler::cliargs::ffi::HandlerCliArgs;
+use log::{debug, error};
+use pushpin::core::log::ffi::{log_init, log_set_level};
+use pushpin::core::settings::{Settings, SettingsError};
 use pushpin::handler::cliargs::{destroy_handler_cli_args, CliArgs};
-use pushpin::import_cpp;
+use pushpin::handler::settings::{ffi, HandlerSettings};
+use std::ffi::CString;
+use std::path::Path;
 use std::process::ExitCode;
+use std::ptr;
 
-import_cpp! {
-    fn handler_init(args: *const HandlerCliArgs) -> libc::c_int;
+fn load_settings(args: &CliArgs, config_file: &str) -> Result<HandlerSettings, SettingsError> {
+    let mut settings = Settings::load(Path::new(config_file))?;
+
+    if let Some(ipc_prefix) = args.ipc_prefix.as_deref().filter(|p| !p.is_empty()) {
+        settings.set_ipc_prefix(ipc_prefix);
+    }
+
+    if let Some(port_offset) = args.port_offset {
+        settings.set_port_offset(port_offset as i32);
+    }
+
+    HandlerSettings::from_settings(&settings)
 }
 
 fn main() -> ExitCode {
     let cli_args = CliArgs::parse().verify();
+
+    let log_file = cli_args
+        .log_file
+        .as_deref()
+        .filter(|f| !f.is_empty())
+        .map(|f| CString::new(f).unwrap());
+
+    // SAFETY: the pointer is either null or a valid C string
+    if unsafe { log_init(log_file.as_ref().map_or(ptr::null(), |f| f.as_ptr())) } != 0 {
+        return ExitCode::from(1);
+    }
+
+    log_set_level(cli_args.log_level as i32);
+
+    debug!("starting...");
+
+    let config_file = cli_args
+        .config_file
+        .clone()
+        .expect("verify sets the config file");
+
+    let settings = match load_settings(&cli_args, &config_file) {
+        Ok(settings) => settings.to_ffi(),
+        Err(e) => {
+            error!("failed to load config file {config_file}: {e}");
+            return ExitCode::from(1);
+        }
+    };
+
     let cli_args_ffi = cli_args.to_ffi();
 
-    let exit_code = unsafe { handler_init(&cli_args_ffi) };
+    let exit_code = unsafe {
+        ffi::handler_init(
+            &cli_args_ffi as *const _ as *const ffi::HandlerCliArgs,
+            &settings,
+        )
+    };
 
     // Clean up the allocated memory
     unsafe { destroy_handler_cli_args(cli_args_ffi) };

src/core/settings.rs

@@ -49,6 +49,9 @@ pub enum SettingsError {
 
     #[error("invalid tcp address: {0}")]
     InvalidTcpAddress(String),
+
+    #[error("must set {0}")]
+    Missing(&'static str),
 }
 
 pub struct Settings {
@@ -306,6 +309,30 @@ impl Settings {
     }
 }
 
+pub struct CommonSettings {
+    pub services: Vec<String>,
+    pub proxy_workers: u32,
+    pub client_maxconn: u32,
+    pub stats_connection_send: bool,
+    pub stats_connection_ttl: u32,
+}
+
+impl CommonSettings {
+    pub fn from_settings(settings: &Settings) -> Result<Self, SettingsError> {
+        Ok(Self {
+            services: settings.list("runner/services")?,
+            proxy_workers: settings.number("proxy/workers")?.unwrap_or(1),
+            client_maxconn: settings.number("runner/client_maxconn")?.unwrap_or(50000),
+            stats_connection_send: settings
+                .bool("global/stats_connection_send")?
+                .unwrap_or(true),
+            stats_connection_ttl: settings
+                .number("global/stats_connection_ttl")?
+                .unwrap_or(120),
+        })
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/handler/handler.pri

@@ -27,7 +27,8 @@ HEADERS += \
 	$$PWD/filter.h \
 	$$PWD/filterstack.h \
 	$$PWD/handlerengine.h \
-	$$PWD/handlerargsdata.h
+	$$PWD/handlerargsdata.h \
+	$$PWD/handlerinit.h
 
 SOURCES += \
 	$$PWD/deferred.cpp \